Heretofore, there has been known a sliding device for a vehicle described in Patent Document 1. The sliding device is provided with a lower rail and an upper rail which are mutually slidably engaged in a longitudinal direction, a lock member (lock lever) pivotably supported by the upper rail at about a center portion thereof and pivotably moved to be disengageably engaged with the lower rail, and a manipulation lever connected to the lock member for pivotably moving the lock member relative to the lower rail in a release direction. The lower rail takes an almost U-letter shape in section and comprises a base portion in a flat shape, vertical walls extending upward from both ends of the base portion, and flange portions turned inward and downward from upper end portions of respective vertical walls. A plurality of engaging teeth like a saw blade are formed on a lower end of each flange portion. Further, the lock member is formed at one end portion thereof with engaging holes engageable with the engaging teeth of the lower rail and is formed at the other end portion thereof with an attaching portion to which a manipulation lever is attached.
In the construction described above, when one end portion of the lock member is pivotally moved upward by a spring force to bring the engaging holes of the lock member into engagements with the engaging teeth of the lower rail, a lock state is brought about to restrain the movement of the upper rail relative to the lower rail. Further, when the one end portion of the lock member is pivotably moved downward by the manipulation of the manipulation lever to separate the engaging holes of the lock member from the engaging teeth of the lower rail, a lock release state is brought about to permit the movement of the upper rail relative to the lower rail.